Magnetic tapes have been long well known in the art of recording as media for recording information. Especially as exterior main recording devices for large-sized high-speed computers or backup storage devices for magnetic disks used in the computers of the type described above, storage media of the type in which a long length of multi-track tape is wound around a tape reel have been well known and are used even at the present. However, it is relatively complicated to mount such magnetic tape wound around a tape reel having a large diameter to load on a storage device and such storage device itself becomes large in size. In addition, the magnetic tape which is loaded in a tape reel case when the magnetic tape is carried or handled is relatively large in size and is not easy to carry it. Furthermore, the tape is unroled when it is unloaded from the case so that it is not easy to handle it. On the other hand, in order to enhance the handling of the magnetic tape, tape cartridges and tape cassettes have been already devised and mainly used in audio equipment, VTRs and so on. The magnetic tapes loaded into the tape cartridges are wider than those loaded in the tape cassettes so that the former have a high storage capacity and consequently are adapted for use as information storage media for computers.
Of such tape cartridges, the tape cartridges of the type in which an endless magnetic tape is loaded and transported within the cartridge and which are adapted to be used in conjunction with the conventional audio equipment are mainly used. Such magnetic tape cartridges are easy in handling, but have a low degree of dust-proof capability because a portion of the magnetic tape is normally exposed the front surface of the cartridge. Furthermore, there are fears that the tapes are damaged by careless handling, contaminants are adhered to the tape from the fingers and the information stored on the exposed portion of the magnetic tape is lost. Therefore, they are not adapted for use in the computers in which the stored information must be maintained at a high degree of reliability. Furthermore, they have a defect that since an endless magnetic tape is transported within the cartridge, the tape transportation speed cannot be increased beyond a certain limit.
In order to solve the above-described problems and defects, a tape cartridge of the type adapted to record and read out the information by drawing the magnetic tape having the ends out of the cartridge was devised and is disclosed in U.S. Pat. No. 4426047. In this tape cartridge, a leader block is attached to the leading end of the magnetic tape and the magnetic tape is drawn out of the cartridge by drawing out of the leader block and then is made into contact with the head so that the information can be recorded in 18-24 tracks in the widewise direction of the magnetic tape. The magnetic tape loaded in such tape cartridge has a storage capacity of the order of 100-300 mega bytes per cartridge. The magnetic media can be easily handled and carried and the storage devices can be made compact in size. Therefore, they are best adapted for use as backup files of small-sized hard magnetic disks or floppy disks and are expected to be further utilized advantageously.
Meanwhile, the tape drives for recording information by using such tape cartridges have been devised and demonstrated. Such tape drives must have the functions of loading the tape cartridge, drawing and withdrawing the leader block from and into the cartridge, permitting the free transportation of the magnetic tape between the take-up reel and the cartridge and so on.
However, in the conventional tape drives of the type described above, the relationship among driving mechanisms which are used to accomplish the above-described various functions is complicated. Especially when it is desired to automatically control a plurality of driving mechanisms, driving means such as a motor must be provided for each driving mechanism so that the whole construction becomes large in size and furthermore a special control mechanism for causing a plurality of driving means to coact with other is needed. As a result, the assembly and control become complicated or inconvenient and the fabrication cost is increased.